Heller, the only GOP senator seeking re-election in a state won by Democrat Hillary Clinton in 2016, faces four lesser-known candidates in the primary after the president persuaded Republican Danny Tarkanian to drop out. Tarkanian is seeking a U.S. House seat, instead.

Heller is expected to face Democratic Rep. Jacky Rosen, who is expected to sail through a six-way primary for her party’s nomination Tuesday.

The toughest choice for Democrats will be a close battle between Clark County Commission colleagues Steve Sisolak and Christina Giunchigliani — each hoping to be Nevada’s first Democratic governor in two decades.

Both candidates have pledged to stand up to Trump and the National Rifle Association.

Sisolak is chair of the powerful governing body for Clark County, which includes the Las Vegas Strip and about two-thirds of the state’s residents. The 64-year-old became a prominent figure in the wake of an October mass shooting outside a hotel-casino on the Strip and he’s been outraising his opponents in the primary.

But Giunchigliani paints Sisolak as being too moderate and has knocked him for receiving an “A-” minus rating from the NRA in 2012.

Giunchigliani, who goes by “Chris G,” is a 63-year-old former state legislator and teacher. She’s earned backing from women’s group Emily’s List and says she’s the most progressive candidate in the race.

Sisolak, who has held more moderate positions in the past, says he’s best-positioned to take on Republican state Attorney General Adam Laxalt in November. Laxalt is expected to win the GOP primary for the governor’s race.

Laxalt, hoping to replace term-limited Republican Gov. Brian Sandoval, is a former lieutenant in the U.S. Navy who has served as the state’s chief prosecutor since 2015. He’s the grandson of former U.S. Sen. and Nevada Gov. Paul Laxalt and son of former U.S. Sen. Pete Domenici of New Mexico.

Laxalt, who is backed by billionaire casino owner Sheldon Adelson and Americans for Prosperity, supported Trump in 2016.

Another key Trump supporter, Tarkanian, is favored in the Republican race for Nevada’s 3rd Congressional District — one of two swing seats in Nevada that Democrats are hoping to hold while they make gains elsewhere and win control of the U.S. House.

Tarkanian, the son of former University of Nevada Las Vegas basketball coach Jerry Tarkanian, has run unsuccessfully for several offices over the past decade.

He is running in a nine-way primary and is expected to face wealthy Democratic philanthropist Susie Lee in the general election. Lee is facing six others in her primary race.

Primary contests for Nevada’s other swing district, the 4th House seat, is expected to produce a November rematch for two former congressmen.

Former Rep. Steven Horsford is leading a six-way Democratic primary for his former seat that includes state Sen. Patricia Spearman. Horsford held the Democratic-leaning seat for one term before losing in 2014 to Republican Cresent Hardy, who is running again this year and leading a six-way GOP race for the seat. Hardy lost in 2016 to Democrat Ruben Kihuen, who announced he wouldn’t seek re-election this year after several women accused him of sexual misconduct.

The most serious primary challenge to an incumbent member of Nevada’s congressional delegation is conservative activist Sharron Angle’s bid for Nevada’s 2nd Congressional District.

Angle is a former legislator who gained national attention in 2010 when she unsuccessfully challenged ex-Senate Majority Leader Harry Reid. She also lost a 2016 bid to become the GOP’s nominee to replace Reid.

She faced criticism for statements on guns, immigration and other issues in the past, but incumbent Rep. Mark Amodei is favored in their battle for the Republican nomination.

Amodei has been in office since 2011 and represents a conservative northern Nevada district.

Voters on Tuesday will also decide inter-party races for Nevada lieutenant governor, secretary of state, treasurer and attorney general. They’ll narrow the field in nonpartisan runoff races for the state Supreme Court and Clark County sheriff. Voters will settle about 30 primary battles for state legislative seats.

One of those races in Nye County pits incumbent Assembly member James Oscarson of Pahrump against Nevada’s most famous pimp, Dennis Hof.

Hof, who starred in the HBO adult reality series “Cathouse,” owns half a dozen brothels that could be threatened this year under proposals to ban such businesses in two of the state’s seven counties where they’re legally operating.

Hof has said the proposed brothel bans are a political attack tied to Oscarson, something Oscarson has denied.

___

Sign up for “Politics in Focus,” a weekly newsletter showcasing the AP’s best political reporting from around the country leading up to the midterm elections: http://apne.ws/3Gzcraw